1. Field of the Invention
The present invention relates generally to self-positioning rupture disk assemblies, and more particularly, to such assemblies wherein the rupture disk includes a positioning part or parts which coact with the supporting members to insure proper positioning of the rupture disk between the supporting members.
2. Description of the Prior Art
A number of different pressure relief devices of the rupture disk type have been developed and used heretofore. Generally, such devices include a rupture disk supported between a pair of support members or flanges which are connected to a fluid flow passageway communicated with a vessel or system containing fluid under pressure. When the fluid pressure within the vessel or system exceeds the design rupture pressure of the rupture disk, rupture occurs causing pressurized fluid to be relieved from the vessel or system by way of the passageway.
The rupture disks utilized heretofore have taken various forms. For example, the rupture disks have been of various pheripheral shapes, most generally circular, and have been of the tension rupture (conventional) or compression rupture (reverse buckling) types. The rupture disks have also been comprised of a single part or multiple parts. In addition, the rupture disks have been of various configurations including flat, domed, conical, truncated conical, etc.
The supporting members utilized heretofore have also taken various shapes, and various forms of gaskets and sealing surfaces have been utilized to effect seals between rupture disks and the supporting members. Various means have also been utilized for clamping the supporting members together, e.g., a plurality of studs and nuts, bolts, ferrule type clamping rings, threaded union connectors, etc.
A problem common to most all of the heretofore utilized rupture disk assemblies is the inadvertent improper installation of the various parts of the assemblies. If the rupture disk is installed upside down in a rupture disk-supporting member assembly whereby the inlet side of the rupture disk is not adjacent the inlet supporting member, improper operation can result. For example, when a reverse buckling rupture disk is installed upside down between supporting members, the fluid pressure required to rupture the disk in tension can be considerably higher than the design reverse buckling rupture pressure of the disk. This in turn can bring about disastrous results.
Various methods and apparatus have been developed and used heretofore to prevent improper installation of rupture disk assemblies, and particularly, to prevent the installation of the rupture disks upside down in the supporting members and/or the misalignment of the rupture disks between the supporting members. For example, U.S. Pat. No. 3,815,779 issued Jun. 11, 1974 discloses a rupture disk assembly wherein the annular flat portion of the rupture disk includes a plurality of apertures therein for engagement by upstanding posts attached to one of the supporting members which fit into recesses disposed in the other supporting member. The spacing of the posts, apertures and recesses is such that the rupture disk can not be installed upside down and the rupture disk and supporting members are automatically aligned. While such apparatus effectively prevents improper installation, it adds significant production costs to the basic rupture disk assembly.
Thus, there is a need for an improved rupture disk assembly which is self-positioning, but which is simple and inexpensive as compared to heretofore utilized self-positioning or self-aligning rupture disk apparatus.